This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are using molecular dynamics simulations to study conformational changes in motor proteins associated with the generation of force and motion. We are studying myosin- and kinesin-family motor proteins. In particular, we are examining changes in the interactions of the nucleotide with the protein at the active site and the concurrent conformational changes in motor proteins. The interactions are complex. The support of the Computer Graphics Laboratory at UCSF is essential for visualization and interpretation of the results of our molecular dynamics simulations, and understanding the interplay between nucleotide and protein.